Air cleaner and silencer unit



u y 1959 J. B. SEBOK AIR CLEANER AND SILENCER UNIT Filed April 22. 1955 212 ETD-I (fade 0h B. Saba/( United States Patent AIR CDEANER AND SIL'ENCER UNIT Joseph B. Sebok, Dearborn, Mich., assignor, by mesne assignments, to Purolator Products, Inc, Rahway, N.J., a corporation of Delaware Application April 22, 1955, Serial No. 503,103

3 Claims. (Cl. 181-35) This invention relates to improvements in an air cleaner and silencer unit, and more particularly to an air cleaner and intake silencer unit or assembly highly desirable for use in connection with an internal combustion engine, and also to a silencer for noises developed in an engine, although the invention may have other uses and purposes as will be apparent to one skilled in the art.

The instant invention is an improvement upon the invention set forth, described, and claimed in a Joseph B. Sebok and Ralph E. Sendelbach copending application entitled Air Cleaner and Intake Silencer Assembly, filed February 23, 1954-, Serial No. 411,612, now U.S. Patent Number 2,822,885.

While the instant invention operates upon the same principles as the invention embodied in the aforesaid copending application, it embodies a more simplified structure. Consequently, the instant invention is not only more economical, but may be manufactured with greater facility and less labor. Further, the instant invention utilizes less parts thereby resulting in a further saving, not only of material and labor, but also of original die costs. Any such reduction in the cost of manufacture is a considerably important factor in a highly competitive field of making and selling air cleaners and silencers. A

definite advance in the art has been made, where a noticeable reduction in the cost of manufacture of a device of this character is attained without any sacrifice of function and efficiency.

In the embodiments of this invention set forth in the aforesaid copending application, a separate partition member was utilized in order to provide the tuning tubes or channels for the volume attenuating chamber enclosed by the outer casing. With the instant invention, the other parts of the structure have been so rearranged that the separate partition is not needed and yet the tuning channels are well defined by virtue of the relative disposition of the other parts, and the mere provision of apertures at predetermined locations determines the length of each of the tuning channels. Thus, with the instant arrangement, it is not necessary to utilize the separate partition member, and to vary the length of that member in accordance with different uses of the invention, so as to adapt the device more particularly for various engines, but it is only necessary to provide apertures or an opening in the inner casing at predetermined points. The location of those apertures or that opening results in establishing the length of the respective tuning channels.

While some of the more salient features, characteristics and advantages of the instant invention have been above pointed out, others will become apparent from the following disclosures, taken in conjunction with the accompanying drawing, in whichi v Figure 1 is a central vertical sectional view through an air cleaner and intake silencer assembly or unit embodying principles of the instant invention; and

Figure 2' is a reduced bottom plan view of the structure of Fig. 1, rotated 90 from the position of Fig. 1.

As shown on the drawings:

Patented July 28, 1959 ice While the instant invention is particularly desirable for use as an air cleaner-intake silencer device or unit, it will be understood that the silencing principle here involved may not only be utilized for the intake of internal combustion engines, air compressors, and other mechanism requiring a supply of air for its adequate operation, but may also be utilized for the silencing of other and various engine and mechanical noises, as will'be apparent to one skilled in the art.

However, for purposes of clarity, the illustrated embodiment of this invention is in the form of an air cleanerintake silencer unit of the character commonly utilized with an internal combustion engine of the automotive type. Further, the illustrated embodiment of the invention is an air cleaner-intake silencer unit of the so-called mushroom type, in that it seats down over and encloses the major portion of the carburetor of an internal combustion engine, although by a simple variation in the casing construction around the clean air outlet, the device may be transformed into the so-called hat type of unit in that it would set above the carburetor and be connected to the intake horn of the carburetor. Such variations as to the proper connection of the device with the carburetor are well within the knowledge of those skilled in the art, and therefore the illustrated embodiment of the invention is by way of example only, and not by way of limitation.

Now, with reference to the drawings, it will be seen that the example selected for illustrative purposes includes an outer casing 1, which may be fabricated of several pieces of material, if so desired. This casing 1 has an indented bottom portion as indicated at 2, terminating in a depending skirt 3 for connection with the carburetor *of an internal combustion engine. In the illustrated instance, the skirt is designed for association with the present Carter carburetor. In order to adapt this skirt for connection with other types of carburetors, it may require a slightly different formation at the termination of the skirt in order to establish proper connection.

The outer casing 1 has a closed top, of which the com tral portion indicated at 4 is preferably removable. Around this central portion the upper part of the casing is shaped in the form of a gasket holding channel as indicated at 5, for the reception of a sealing gasket 6. The removable cover 4 rests over the sealing gasket 6 so that the connection is air tight. This cover is centrally apertured as indicated at '1 to accommodate an upstanding bolt (not illustrated) which is secured to the carburetor of the internal combustion engine. A wing nut over the top of that bolt when tightened holds the entire unit firmly in position upon the carburetor.

Preferably carried by the removable cover 4, as by a lock seam or in any equivalent manner, is a depending filter holding shell including an outer wall 8 which turns underneath and is connected to an inner wall 9 concentric therewith but spaced therefrom. Between these two walls is a filtering mass 10 of any suitable material, such as wavy copper wire, curled cattle tail hair, sisal fiber, etc. The bottom of the filter holding shell 8-9 is perforated to permit air to pass through the filter mass. Also depending from the filter holding shell is a baflle 11 for association with a liquid sump,.to limit the amount of sump liquid entering the filter mass by virtue of the traveling air. 7

An inner casing 1 2, spaced from the outer casing, and spaced from the filter retaining shell 8, is provided with a side wall having an outwardly turned upper margin as indicated at 13 to rest upon the aforesaid gasket 6 at the top 'of the outer casing. The bottom part of'this inner casing" 12 is shaped as indicated at 14 to define a liquid sump for cleansing liquid disposed beneath the filter mass 10. This inner casing bottom portion rests C9 upon a gasket on the bottom of the outer casing around the aforesaid skirt 3, so as to establish an air tight seal therebetween.

The bottom of the inner casing extends upwardly above the gasket 15 and terminates in an upwardly extending flange 16 above the aforesaid skirt 3 of the outer casing, and around that flange 16 is disposed a gasket 17 upon which the filter holding shell seats to establish an air tight seal.

From the foregoing description, it will be noted that the cover 4 together with the filter holding shell and filter mass is removable as a unit. The inner casing 12 containing the liquid sump is removable separately from the cover and filter mass, as well as separately from the outer casing. The outer casing 11 may then be removed from the carburetor, if so desired, although there is no need to remove the outer casing in order to service the air cleaner portion of the structure. Upon removal of the inner casing 12, the liquid sump may be drained of its liquid and collection of contaminants, and refilled with the proper amount of fresh cleansing liquid, after which it is a simple expedient to again assemble the parts for operation.

For silencing purposes, the outer casing 1 houses a volume chamber 18 which, in the illustrated instance, completely surrounds the inner casing 12. This volume chamber is preferably of predetermined size corresponding to the range of sound wave lengths desired to be silenced for the particular engine with which the unit is associated. In order to properly tune the volume chamber, tuning channels should be provided of predetermined length, and these channels are associated with the air inlet, and in effect are an integral part of the volume chamber. In the illustrated instance, the channels are provided by the eccentric relationship between the inner casing 12 and the outer casing 1, the inner casing being closer to the outer casing at one point, than at any other point, in view of the fact that the casings are round. Of

course, the casings could be any other desired shape and it is only necessary to have the inner casing closer to the outer casing in the region of the air inlet. in the illustrated instance, the outer casing is provided with an air inlet at 119, and the inner casing is closer to the outer casing immediately adjacent that inlet than it is elsewhere. Thus, the inner casing and the outer casing define a pair of tuning channels, tubes, or conduits, as indicated in Fig. 2 at 2% and 21. These channels are of predetennined length, and the length of each channel is determined by the provision of an opening in the inner casing wall to admit air to the air cleaning portion of the structure. In the illustrated instance, the channels are substantially of a length half way around the inner casing and as illustrated are both of the same length, although that is not essential, and the termination of each channel is established by the first of a series of openings 22 in the inner casing wall, near the top thereof, to admit air to the passage 23 between the inner casing Wall and the filter holding shell 8. This air enters through the openings 22., passes downwardly through the annular passage 23, over the liquid sump 14 and battle 11, upwardly through the filter mass 10, inwardly beneath the removable cover 4, and into the central compartment defined by the shell 9,- fiange 16 on the inner casing, and the skirt 3 on the outer casing, from whence the air may directly enter the carburetor of the internal combustion engine.

From the above description, it Will be seen that, in effect, the spacearound the carburetor, the space occupied by the filter mass, theannular passage 23 for the air, and the tuning channels 29 and 21 are all apart of .the volume chamber 18, and the incoming'air passes directly through that volume chamber. Noise emanating from the internal combustion engine will travel in the reverse direction, that is, it will first enter the space inside the shell 10, then travel through the filter mass, up the 4 annular passage 23, and into the volume chamber and ultimately into the tuning conduits 20 and 21. At the present writing, the exact theory of operation of the 1nstant invention is not known, but it has been proven highly effective in actual practice. It is believed at the instant writing that the tuning conduits 20 and 21 function as an acoustical short circuit for the volume chamber 18 so that the sound rather than emanating through the inlet opening 19 remains in the volume chamber and becomes neutralized. This theory, of course, presupposes that the impedance to the travel of sound waves at the very opening 19 is far greater than the impedance to the travel of the same sound waves from one of the tuning channels into the other channel. In any event, not only is a single predetermined fundamental engine tone neutralized by the instant construction, but also a range of engine sound are neutralized so that the same structure may be utilized for a number of dilfere-nt engines without any alteration whatever, all as more fullypomted out in the aforesaid co-pending application.

With the instant invention, it will be especially noted that the fundamental parts of an oil bath air cleanerintake silencer unit are relied upon toestablish the tuning channels 20 and 21 which govern the range of sound waves attenuated by the volume chamber in the outer casing. This is accomplished by the offset or eccentric relationship between the inner casing housing the liquid sump and the outer casing, and it will further be noted that it is a simple expedient to determine the length of these channels by the location of the opening or openings leading to the air passageway 23 inside the inner casing. The disposition of the openings 22 on either side of the inner casing 12. determines the length of the respective tuning channel. Thus, the entire structure may be modified through a relatively great range of different tunings to accommodate various internal combustionengines, with no more difiiculty in the manufacture, than-the mere location of openings provided in the inner casing 12. No special dies are required for the various units for the different engines, and no difficulty is provided in manufacture, so that the instant invention results in a noticeable reduction in the cost of manufacture of a unit of this character.

It will be understod that modifications and variations may be efiected Without departing from the scope of the novel concepts of the present invention.

1 claim as my invention:

1. In a silencer for engine noises, an outer casing having an air inlet opening, an inner casing disposed within the outer casing and extending between the top and bottom thereof to provide a volume chamber for sound attenuation, said inner casing positioned nearer to the outer casing adjacent said inlet opening than the side of said inner casing opposite said inlet opening, said inner casing being imperforate a predetermined distance therearound in the part nearer said inlet opening to provide tuning channels for said volume chamber, said inner casing having an opening therein beyond said channels, and said casings having an opening leading from the inside of said inner casing.

2. In a silencer for engine noises, an outer casing having an air inlet opening, an inner casing disposed within said outer casing and extending between the top and bottom thereof to provide a volume chamber for sound attenuation, said inner casing positioned nearer to the outer casing adjacent said inlet opening than the opposite side of said inner casing away from said opening, the inner casing being imperforate adjacent said inlet opening and a predetermined distance extending in opposite directions therefrom to define tuning channels for said volume chamber, the inner casing having opposed openings therein determining the length of said channels, and said casings having an opening leading from the inside of the inner casing.

3. The silencer of claim 2 wherein said inner casing 5 is cylindrical, said tuning channels extend equal distances from said inlet opening, and said channels and the interior of said inner casing communicate with said volume chamber and in efiect form a part thereof.

References Cited in the file of this patent UNITED STATES PATENTS 6 Sebok June 19, 1951 Dreznes July 8, 1952 Sebok et a1. Oct. 12, 1954 Amlott June 5, 1956 Sebok Aug. 28, 1956 McMullen Apr. 23, 1957 Heller et a1. Aug. 27, 1957 Sebok et a1. Feb. 11, 1958 

